serde/test_suite/tests/compile-fail/unknown-attribute/field.rs

#[macro_use]
extern crate serde_derive;

#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
struct C {
    #[serde(abc="xyz")] //~^^ HELP: unknown serde field attribute `abc`
    x: u32,
}

fn main() { }